Signal apparatus for combustion control.



'F. D. POTTER.

SIGNAL APPARATUS FOR COMBUSTION CONTROL.

APPLICATION FILED FEB. 15, I916.

Patented Nov. 13, 1917.

. INVENTQR Aym W v 1 .1 ATTORNEYS FREDERICK ID. POTTER, OF LINDEN, NEWJERSEY.

SIGI TAL APPARATUS FOR COMBUSTION CONTROL.

Specification of Letters Patent.

Patented Nov. 13, 1917.

Application filed February 15, 1916. Serial No. 78,369.

To all whom it may concern:

Be it known that I, FREDERICK D. Poms,

a citizen of the United States, and a resident of Linden, county ofUnion, and State of New Jersey, have invented certain new and usefulImprovements in Signal Ap aratus for Combustion Control, of which thefollowing is a specification. a My invention relates to signal apparatusfor combustion control, and while the invention is illustrated anddescribed hereinas applied to a steam boiler and its setting, it is tobe understood that the invention may be made use of in connection with avariet of apparatus where it is desired that t ere 'be presentedindications or signals readily perceptible to a human sense or senses ofunfavorable conditions of combustion, in pursuance whereof theundesirable condi-' tions may be remedied or controlled by anyappropriate means.

I have found that where the heat of a fire is utilized by passing theflame and heated gases along in contact with the surface to be heatedas, for example, in a steam boiler installation, that the efi'iciency ofthe apparatus is very closely de endent upon the maintenance of a bed ofel as nearly uniform throughout its extent as can be secured, and inparticular that if there are any places where the layer of fuel is muchthinner than at other places, or if, as sometimes happens, there is ahole in the fire, that is, a space where the incoming air for supplyingoxygen to the fire is permitted to pass directly into the combustionchamber without passing through a layer of fuel and becoming heated insuch passage, the heating efliciency falls off very rapidly and thetemrature throughout the combustion chamer and in the region where theheat is given up to the object or objects being heated is lowered to amarked degree, and this frequently happens without the fireman orattendant being aware of it until it progresses to a noticeable extentas by the lowermg of the steam pressure on the ga e.

An object of the present invention is the provision of means whereby anindication perceptible to a human sense or senses 1s given on any suchlowering of temperature as soon as or very shortly after 1t occurs sothat the proper remedy may be applied without unnecessary delay as, forexample, when the cause of the objectionable condition is a hole in thefire or a thin spot, by I inthe arrangement of the actuating mechai nismfor the indicating apparatus-in a position between regions containinggaseous materials under differing conditions of pressure, speed oftravel and the like,which dif-v ferences are short circuited and theactuatmg apparatus placed in or in communication with such short circuitto insure the actuation of the indicatin apparatus with the greatestpossible quiciness and certainty. A further object of my inventionconsists n the provision of a number of successive mdicatmg means cominginto operation sue-V cessively as the objectionable condition increasesas, for example, in the case of acontrol for a boiler furnace byinsuring the ringing of a bell in the fire room as the first indicatingmeans, thus drawing the attention of the fireman or boiler attendant toa condition to be remedied, and if the objectionable condition is notspeedilyremedied a further si al, as a bell in the superintendentsoflie, may be rung, thus bringing the condition of the fire to the attentionof some person having supervisory authority and insuring the prompt andefiicient attention of the fireman or attendant in immediate charge inorder to prevent vthe giving 'out of subsequent signals which wou d cometo the attention of his superior. Another object of the inventionconsists in thearrangement of the signal actuating mechanism in such amanner as that it will respond readily to changes of temperature in thefurnace gases, while at the same time it is protected from excessiveheat and is insulated from the walls and surfaces in its immediateneighborhood so as not to respond to any considerable extent to the heatconditions prevailing therein and which vary but slowly. Other andfurther objects of my invention will appear in connection with thefollow-- ing description thereof and be pointed out in my claims,'andwith the foregoing and related objects in view, my invention consists inthe arts, improvements and combinations herem set forth and claimed;

It is to be understood that the apparatus shown and described herein isfor the purpose of illustration only, and that my invention is notconfined thereto but is as broad as my claims.

In the drawin forming part of this specification, and w erein the samereference numerals are uniforml used to designate the same parts througiout, Figure 1 is a vertical cross-sectional view illustrating one formof signal operating device in accordance with my invention. Fig. 2 is anelevational view at right angles to Fig. 1 with the cover removed. Fig.3 is a cross-sectional view taken on the line 33, Fig. 1. Fig. 4 is adiagrammatic and cross-sectional view of a boiler setting showing thepreferred location of the opening in the bridge wall, and Fig. 5 isv ahorizontal cross-sectional view taken on the line 55, Fig. 4.

Reference numeral 10 designates one type of boiler setting'generally,and which is of such character as that the path of travel of the flameand heated air from the fire in reaching the-space back of the bridgewall 11 is indirect. In the type of setting shown, the boiler is of thewell known Babcock type, and the flame and heated gases travel from thefire on the grate bars 12 upwardly over the baiiie 13 and downwardly tothe rear of the bridge wall 11 until they pass beneath the baffle 14 andupwardly out of the stack 15. My invention may be used, however, whenapplied to boiler furnaces, with boilers and settings of differenttypes. With the type shown, the path of travel of the flame and heatedair from the fire-box to the space behind the bridge wall is indirect sothat there the conditions of pressure, speed and duration of gas traveland the like are different in these two neighborhoods. Means of directcommunication from the fire-box to the space behind the bridge wall areprovided. Such communicating passage indicated at 16 on the drawings is,however, comparatively small so as that the escape of such smallquantity of gas and vapors as passes therethrough .does not interfere toany material extent with the combustion and does not detract materiallyfrom the heating eflect produced by the fire. Such passage being a shortcircuit, direct from the firebox to the space behind the bridge wall,whereas the path normally traveled by the flame and gases is circuitousas, for example, up over and back down behind the baflie plate 13, itresults that the flame and gases prefer to travel through the opening 16by reason of the difference of pressure, etc. on the two sides of thebridge wall, so that while the fire is burning there is always acirculation of the flame and heated air or gases through the opening 16in the bridge wall 11 and into the space 17 back of the bridge wall, andthe temperature of the sage 16. In order that such heat operableactuating means may be protected somewhat from the extreme heat which isencountered if placed directly In the passage 16, I preferably placesuch apparatus in a side passage communicating with the passage 16 inthe bridge wall. In the form shown such side passage 18 extends from thepassage 16 to one of the side walls of the boiler setting, the passage16 as shown in Fig. 5 being preferably placed fairly close to such sidewall 10 of the boiler setting 10 in order that the passage 18 may extendto the outer face of the side Wall and still be comparatively short.

Any device whereby movement is produced by changes of, temperature whenplaced within the passage 18 or otherwise in communication with thepassage through the bridge wall 11 may be made use of. In the form showna tube 19 of material readily expanded by heat as, for example, a coppertube, is provided and serves as a thermostatic or heat expansiblemember. The tube 19 is anchored at its outer end 20 in any suitablemanner. Within the tube 19, and firmly secured thereto at the end- 21opposite the end 20 as by means of a rivet 22, is a rod 23 which isprefereably of a material whose cocflicient of expansion is zero or asnear thereto as possible, and such rod 23 preferably extends beyond thetube 19 and beyond the passage 18 at its outer end 24, said projectingend 24 being moved in or out slightly as the member 19 contracts andexpands, and the arrangement serving as a means whereby mechanicalmovement is obtained responsive to temperature changes in the passages16 and 18.

This thermostatic means is preferably arranged in the passage 18 in suchmanner as to be responsive to and readily affected by changes oftemperature in the gases contained in the passage, and at'the same timeto be insulated as thoroughly as possible from the walls of the passage,the temperature at which walls, at least over short periods, remainssubstantially unchanged. In the form shown the tube 19 is received in anouter tube 26 which is preferably of metal, as iron, and is'preferablyformed with comparatively thin walls so as to be sensitive to heatchanges taking place in the passage 18. The tube 19 preferably rests onthe bottom of the tube 26 in which it is contained, as shown in Fig. 1.Any means for insulating the thermostatic member from the side walls ofthe chamber wherein it is received, as the passage 18, may be resortedto, as, for example, the surrounding air when it is supported entirelyout of-contact there- 'with. In the form of construction shown there areprovided for this purpose three tubes 27 which are of material whichpreferably is as effective a heat insulator as can be secured. For thispurpose these tubes may, for example, be made of porcelain, and the tube26 containing the tube 19 may rest on the top of two of the tubes 27,the third of the tubes 27 resting on the bottom of the passage 18 andserving as a support for the other two of the tubes 27 with the tube 26resting thereon and out of contact with the wall of the passage 18. Whenparts are provided and arranged in the manner shown and described, itwill be evident that the tubes 19 and 26 are substantially insulatedfrom the walls of the chamber 18 and may therefore respond to changes oftemperature of the air and gases contained in such chamber, and at thesame time are protected from the excessive heat to which they would beexposed if arranged directly in the bridge wall passage 16. Y I

Any suitable means for utilizing the movement of the end 24 of the rod23 to operate a signal or indicating device or devices which may beperceptible to a human sense or senses may be resorted to, and any typeof signal or indicating devices adapted for such purpose may be used. Inthe form shown awall plate 29 is secured to the outer face of the wall10 and is provided with an opening 30 opposite the outer end of thepassage 18, and secured to said wall plate, as by means of the screw 31,is a support 32 upon which parts of the operating mechanism arearranged, and WhlCh is preferably formed as a solid metal casting inorder to provide a substantially rigid support for the parts mountedthereon, and this support and apparatus are preferably covered, as bymeans of a cover box 33, and

the entire casing is tightly closed when suchcover is in place.

In the form of construction shown the thermostatic device is secured toand is removable from the indicator support 32, the end 20 of the tube19 being firmly anchored in such supporting member32. The member 32 isprovided at its rearward side with an extending sleeve 34, which fitswithin the opening 30 in the plate 29 and within which sleeve 34 thetube 26 is received and held. The tube 26 is shown as extending beyondthe thermostatic device, but may be longer or shorter than as shown, andif desired may be dispensed with altogether along with the porcelainsupporting tubes 27.

Any deposits of soot or the like which may be produced takes placeprincipally within the passage 18 and may be blown out from time totime, as by inserting a blower nozzle through the pipe 35, the outer endof which is closed at cap 35'. L

The end 24 of the rod 23 is provided with an adjustable extension 36. Inthe form shown, a bore 37 is formed in the portion 24 of the rod 23,which said portion 24 is slotted, as shown at 38, and provided with asleeve or collar. 39, serving to grip the slotted portion of the end 24of the rod 23 upon the rod 36 in the familiar manner, in which drillchucks are held. The collar 39 and the part 24 of the rod 23 may bethreaded, if desired to secure an extra firm hold of the extension 36.With such arrangement the extension 36 may be adjusted and secured inany desired relation to the rod 23, as will be understood. The rod 36has formed therein an elongated slot 40 which receives a cross pin 41ina lever 42 supported upon pivots 43, 43 which, in the form shown, areplaced a short distance below the axis of the cross pin 41. Springmeans, as a leaf spring 43, are applied to the lever 42 and tend to turnit to the right, as the parts are shown in Fig. 1. As will be evident,when the extension 36 is adjusted as shown in Fig. 1, pull on the rod 23and extension 36 due to expansion of the tube 19, results in the movmgof the lever 42 toward the left, as shown in such figure, and as thetube 19 contracts upon the temperature fallingfthe lever 42 turns towardthe right under the influence of the spring 43. When the Whole device iscooled off as, for example, when the boiler is out of use, theelongation of the slot 40 permits further contractile movement of thetube 19 and resulting movement to the right of the extension 36 of therod 23 freely and without danger of breakage of the parts. By means ofthe adjustment which may be obtained by the collar 39, any permanent setin the thermostatic member may be compensated for by adjusting theextension in or out with respect to the rod 23, according to thecharacter of such permanent set.

As will be readily observed, the lever 42 serves to multiply veryconsiderably the movement produced by contraction and expansion of thetube 19, and such lever is provided, preferably toward the end of itslonger arm, with means for operating one or more signal or indicatingmeans, this being accomplished in the form of construc tion shown byclosing one or more electric circuits by bringing contact memberscarried by the lever 42 into contact with coiiperating contact memberssuitably placed in the path thereof.

In the particular form shown, the upper portion of the supporting member32 is provided with a cylindrical bore 45, wherein is rotatably receiveda cylindrical rod 46 which may be adjusted lengthwise as by means of setscrews 47, 47, one of said screws 47 being arranged in a plate 48 othertimes as by the which is removably secured to the member 32 as by meansof a screw 49, which may also serve as a means for attaching a lead wire50. The rod 46 has a vertical slot 51 formed therein, and an opening 52is formed in the member 32 opposite the slot 51. FW- otally mountedwithin the slot 51 is an arm 53. Said arm is extended upward beyond itspivot 54, and provided wlth a flat face 55 normally resting against asimilar flat face 56 on a member 56' firmly secured within the slot 51in the m ber 46- As will be seen, the arm 53 is normally retained withthe faces 55 and 56 in close contact but is free to swing in theopposite direction, and said arm and the member 46 in which it iscarried may be adjusted bodilg by means of the screws 47, 47, the arm'eing preferably inclined somewhat to the right, as shown in Fig. 1, sothat the action of gravity results in maintaining the faces 55 and 56 incontact. A'spring may be used for this purpose but is ordinarilyunnecessary and has not been illustrated. The arm 53 and member 46 inwhich it is mounted may also be swung in a direction at right angles tothat in which the arm 53 turns on its pivot, the member 46 beincylindrical and received within a cy indrical opening 45. The arm 53 isprovided with a plurality of contact screws 58, 59 and 60 and also witha projecting stud 61, the latter being placed laterally of the contactscrews, as shown in Fig. 2. Said screws 58, 59 and 60 are preferablylaced at different distances from the pivot 54 on which the arm 53turns, so that the extent of movement of such screws will vary accordingto the distance thereof from the pivot 54.

The lever 42 is provided with members for cotiperating with the contactscrews 58, 59 and 60 andstud 61, and in the case of the screws 58 and 59and stud 61, for completing an electric circuit for operating a signalor indicator, as an electric bell or light or the like, whereas when thescrew 60 is in contact with the member 42, no such circuit is passed andno signal is given. In the form shown such effect is obtained bysecuring a plurality of alternately arranged insulating and conductingmembers on the member 42. As shown immediately adjacent to the lever 42and at the side thereof next to the arm 53 is a contacting plate or band62 which is adapted to make contact with the stud 61 when the arm 53 isswung by turning the rod 46 on its axis in the bore 45. The plate orband 62 has a lead wire 63 connected thereto and which may lead to anysuitable signal or indicating means which, as is the case with all theindicating means, is in circuit with 62, and has its upper end oppositethe screw 60. Next outward from the lever 42 is a contact plate or band65 which is still shorter and has its upper end opposite the screw 59and has connected thereto at its lower end a lead wire 66 leading to alight, hell or the like signal. Next outward from the lever 42 is aninsulating plate 67, and finally there is a contact member 68, the upperend whereof is placed opposite the contact screw 58 and which has at itsoppo site end a lead wire 69 connected thereto and forming part of anelectrical circuit including a suitable indicating device. In the caseof the last circuit referred to, a signal lamp 69 is shown in Fig. 1,and similar or other signal devices may be made use of in the othercircuits.

The operation of the device is as follows. When the fire is burningsatisfactorily and a sufficiently high temperature is maintained, thethermostatic tube 19 being expanded by the heat pulls the lever 42toward the left (Fig. 1) against the spring 43 and maintains it out ofcontact with all of the contact members on the arm 53. Whenever, for anyreason, the temperature in the fire-box and therefore in the passages 16and 18 falls and the tube 19 contracts, the lever 42 moves to the rightunder the influence of the spring 43. The contact screw 58 is preferablyset so that it will be first to complete a circuit for operating anindicating device, and such indicating device, as already stated, may bearranged in the boiler room so that onlv the fireman or boiler attendantwill observe it. The action of the indicating device, as the sound of abell, will bring to his attention the fact that the temperature in thefire chamber is falling, and he may take such steps as are needed tocorrect the objectionable condition, as by throwing fuel u on the thinspace in the fire, or by such 0t er treatment as may be necessary, andwhen the temperature rises, as a result of proper conditions having beenrestored, the tube 19 expands by reason of the rising temperature andbreaks the circuit, and the alarm is no longer sounded.

If, however, the cause of the falling temperature is not remedied by thefireman or boiler attendant, and the fall in temperature continues, andthe tube 19 likewise continues to contract, the screw 59 will next comeinto contact with its coactin member and cause an electrical circuit, anthis circuit may be arranged to operate an indicating devlce, as a hellor lamp, in the ofiice of the superintendent or other person having theplant in charge, and in this manner his attention will be directed tothe fact that proper firin conditions are not bein maintained for t eboiler to which such mdicating member belongs, thus giving the man incharge of the plant an eflicient means of determming when the firing isbem properly done and when conditions are sue as to reuire his personalattention, and 1n this way t e man in charge can very readilyvdistmguishbetween competent and incompetent help in the boiler room. By pro eradjustment of the screws both the si a s operated by the screws 58 and59 may e made to be sounded together, or the contact-made by the screw58 may be terminated as the lever 42 and arm 53 are moved to-the right,the contacting of the screw 59 throwing the screw 58 out of contact.

If the boiler is shut down it is desirable that the signals shall not besounded or otherwise actuated, and it is for this reason that the screw60 opposite the insulating plate 64 has been provided.' With sucharrangement when the movement of the lever 42 to the right is greatenough to bring the insulating plate 64 into contact with the screw 60the screws 58 and 59 if properly adjusted may be thereby thrown entlrelyout of contact, thus reventing the further op-.

eration of an o the indicating means.

'It is desira le that the setting of the arm 53 may be standardized andit be so arranged as that while the arm 42 and its contact members areout of contact with the corresponding members on the arm 53 when properfiring conditions are maintained, yet that they be so close together asthat any drop in temperature which requires attention may be readilyindicated by proper contacts being made. In order to facilitate suchsetting of the parts the setting stud 61 heretofore referred to'has beenprovided. By swinging the arm 53 and the rod 46 sli htly, such swingingbeing toward the le t, as shown in Fig. 2, the stud 61 may be broughtopposite the contact plate 62, and their being brought into contact maybe made to operate a signal, as a light or bell, and while such signalis being operated the screws 58, 59'and 60 may be adjusted so that thenecessary slight movement of the arm 53 will result in giving thedesired signals upon movement of such arm. One such setting of screws58, 59 and 60 may be made which is substantially permanent, and if thedevices should not properly respond to changes in temperature it is onlynecessary to move the arm 53 and the member 46 in which it is carried,bodily by means of the set screws 47, thus afiording simple means forcompensating for any changes which may occur and making it readilypossible to bring the signal apparatus back to proper position from timeto time as may be needed.

It will be seen that my invention may be embodied in a variety ofconstructions and that it has numerous points of advantage. While I haveshown a particular construction in which it may be embodied, theinvenindirectly from the combustion chamber, a

passage provided for directly connecting the chambers, and means forindicating changes of temperature of the gases passing through saidpassage, substantially as set forth.

2. In combination, a combustion chamber, a chamber into which thecombustion gases pass lndirectly from the combustion chamber, a passageprovided for directly connecting the chambers, thermostatic means inconnection with said passage, and signal means operated from saidthermostatic means, substantially as set forth.

3. In combination, a combustion chamber, a chamber into which thecombustion gases pass indirectly from the combustion chamber, a passageprovided for directly connecting the chambers, there being a secondpassageway communicating with the first passageway, theremostatic meansin said second passageway, and signal means operated from sa1dthermostatic means, substantially as .set forth.

4. In combination, a combustion chamber, a chamber into which thecombustion gases pass indirectly from the combustion chamber, a passageprovided for directly connecting the chambers, there being a secondpassageway in communication with the first passageway and extendingtherefrom at an angle, thermostatic means in said second passageway, andslgnal means operated from said thermostatic means, substantially as setforth.

5. In combination, a combustionchamber, a chamber into which thecombustion gases ass indirectly from the combustion chamer, a passageprovided for directly connecting the chambers, there being a secondpassageway communicating with the first passageway, thermostatic meansin said last named passage and having a heat movable extensionprojecting therebeyond, and signal means operable by the movement ofsaid extension, substantially as set forth.

6. In combination, a combustion chamber, a chamber into which thecombustion gases pass indirectly from the combustion chamber, a passageprovided for directly connecting the chambers, there being a secondpassageway communicating with the first passageway, a casing with whichsaid second passage communicates, thermostatic means in the secondpassage and having a heat movable member projecting into said casing,means in said casing for opening and closin an electric circuit, andsignal means opera is upon the closing of such circuit, substantially asset forth.

7. In combination, two chambers, from one of which heated gases pass tothe other indirectly, a short circuit passageway directly connecting thechambers, thermostatic means operable by changes of temperature in saidpassage, and signal means operated from said thermostatic means,substantially as set forth.

8. In combination, a pair of chambers through which heated gases arepassed, a wall separating said chambers around which the gases pass, apassageway leading directly through said wall, thermostatic meansoperated by changes of temperature in said passageway, and signal meansoperated from said thermostatic means, substantially as set forth.

9 In combination, a passageway through WhlCll heated gases are directlypassed, a second passageway in communication therewith, thermostaticmeans in said second passageway, and signal means operated from saidthermostatic means, substantially as set forth. y

In testimony that I claim the foregoing, I hereto'set'my hand, this 10thday of February, 1916.

FREDERICK D. POTTER.

Witnesses:

M. A. JOHNSON, H. Tnan'rvnmn.

